High-water control for multiple-drum boilers.



H. DUFF 8: H. LE H. SMITH.

HIGH WATER CONTROL FOR MULTIPLE DRUM BOILERS.

APPLICATION FILED AUG. I9. I913.

Patented Nov. 2, 1915.

2 SHEETS-SHEET I- 16 9 ATTORNEYS COLUMBIA PLANOGRAFH CO.,WASHINGTON, D.C.

H. DUFF & H. LE H. SMITH. HIGH WATER CONTROL FOR MULTIPLE DRUM BOILERS.APPLICATION FILED AuG.I9. 1913.

1 1 59, 1 93 Patented Nov. 2, 1915.

2 SHEETS-SHEET 2.

ATTORNEYS COLUMBIA PLANOGRAPH 10.. WASHINGTON. D. c.

UNITED MW M m HOWARD DUFF AND HARTLEY Lair. SMITH, or'NEw YORK, N. Y;

HIGH-WA'IER. CONTROL r03 MULTIPLE-DRUM- Bo'ILEnsQ Specification ofLetters Patent.

7 Application filed August 19, 1913. Serial No. 785,553. I

Control for Multiple-Drum Boilers, of-

which the following is a full, clear, and exact description.

This invention relates to an improved con- 7 trolling system formultiple drum boilers,

and more particularly to a high water control system adapted for use inconnection with a feed water regulator or for general' notification ofhigh water with or without automatic regulation of it, both in referencetomultiple drum water tube boilers, causing the regulation or thenotification to be in accordance with the water'level 1n the drum wherethe level is highest, the importance of this being the' fact that thehigh water level is of most significance in multiple drum water tubeboilers, especially in preventing surging of the water and consequent inury to superheaters, steam pipe lines or machinery.

With the above and other objects in view, the invention resides moreparticularly in the peculiar combination and arrangement of parts whichwill be illustrated as a preferred embodiment in the accompanyingdrawings and described in the specification. Reference is to be had tothe accompanying drawings forming ,a part of this specification, inwhich similar characters of reference indicate corresponding parts inall the views, and in whichf Figure 1 is a front elevation of aplurality of steam drums of a water tube steam boiler, with the improvedhigh water control system connected thereto, in connection with a feedwater regulator and main feed water pipe, it being understood that thefeed. water regulator shown is merely illustrative of the application ofthis invention in connection with a feed water regulator, andany otherfeed water regulator might have been shown, or the application of; theinvention might have been shown in connection with a scheme of generalnotification of high water i heat rs erle s ,teels e epreesjte behighest, with or without any attempt at automatic regulation of thewater flow through the feedline; Fig. 2 is an enlarged detail sectionalview of one of the check valves employedin the system; and Fig. 3

PatentedNov-.2,1915;

is a view similar to Fig. 1 showing one of j the drums, the drum and theexpansion tube of the regulator which happens to have been chosen forillustrative purposes, being shown partly in section, it beingunderstoodthat some form of regulator not making use of an expansiontube might have been chosen for purposes ofillustration.

In high pressure boilerwork, of high capacity and water tube design, itis common touse several drums rather than one, and

experience shows that there is very considerable difierence inwater'level between the different drums, such difierence beinglrregul'ar n magnitude and locat on, so that in one drum 1t 1s ,hlghforone moment and sults in a more or less-periodic surging of water levelwhich fluctuates between the different drums as the wave of Ta head ofwater nio'vesfrom one drum to another with a time interval determined bythe natural in another, the next; This very often ,re-

water level in agage glass or water column attached to one of theseveral drums of a multiple drum boiler, regardless of where thewatermay be'in the other drums. Thus, when a feed water regulating device isused it'is acommon practice to so connect it that one of its functionsis to preserve this accepted single drum level either as nearlyunchanged-as possible while the rate of feed water flow varies from zeroto a value much be 0nd an attainable steamin krate or to v h V 7 makethe accepted level abovef-referredto 1 the one preserved at the averagerateof feed water flow and then control theflow {as an inverse functionof the rise or fall a'bove and below this normalorj average level.'WVith either of these constructions, however, the

water levels in the drums to which the'feed water regulator is notconnected are continually :fluctu'ating, and these fluctuations do notaffect the regulator, and therefore here was 19 11 th i o e ss-7511ma 1The same may be said of systems of mere general notification of highwater level with or without regulation of feed water flow; thenotification is given only when high water occurs in the drum to whichthe device is connected, and high Water in any of the several remainingdrums of the multiple drum boiler may do damage unhindered.

It is the main object of the invention herein being described toovercome the above mentioned defects and control the feed water flow orgive general notification, as the case may be, in accordance with thehigh water level in whichever one of the several drums may happen at anymoment to have the highest level.

It is a not uncommon practice to connect feed water regulators to themud drum or some other part of the boiler in which a free surfaceseparating water and steam does not exist, instead of connecting theregulator to a water column or gage glass or in any other way, directlyor indirectly, to any one steam drum of a multiple drum boiler. Whenthis is done the feed water regulator is acted upon by a head of waterwhich varies as the average head in all the multiple steam drums, andthereby causes the rate of feed water flow to be determined by theaverage water level in all the steam drums. This is not generallysatisfactory because, as stated before, the water levels in thedifferent steam drums fluctuate and in any one of them the water levelmay be so much higher than the average water level in all of them as tocause surging. of water from that drum over into the superheaters, ordirectly to the steam lines, and so be the cause of damage. It is thusapparent that the highest water level is of much the greatest importancein multiple drum water tube boiler practice for the purpose of automaticregulation of the feed water flow or for general notification of highwater. The surges of water resultin carrying the same over into thesteam lines in boilers with or without superheaters and the water so carried over, commonly called water slugs, occasions trouble and damage tosuperheaters, steam pipe lines, engines or turbines, and this troubleand damage will be entirely avoided where a feed water regulator iscaused to be acted upon by and respond to the water level in that drumin which the water level happens at any moment to be highest, this levelshifting about in an irregular but often more or less periodic mannerfrom one drum to another. For accomplishing these functions, that is,for causing the feed water regulator to be afiected by and therebyexercise control in accordance with the water level in the drum wherethe level chances to be highest among the various nd varying waterlevels of a multiple drum boiler, or for causing general notification tobe given of undesirable high water level, we have illustrated anembodiment in the accompanying drawings.

Referring to the drawings, the numerals 10, 11 and 12 designate aplurality of steam drums of a multiple drum water tube boiler, and thenumeral 13 designates an expansion tube of a feed Water boiler of thesubmerged tube type, which is mounted on a support h and which isdisposed in an inclined position, as shown. The tube 13 is mounted in ahollow casting 16 at its lower end, and this end is on a common levelwith the lowest point of a water gage.

The highest point of the expansion tube is at an elevation correspondingto the normal or safe level of the water in any of the drums, and thisupper end of the tube of the regulator is connected to the steam spaceof the drum 10, or of any other one of the steam drums carrying thelevel gage, by means of piping indicated by the numeral 17. The upperend of the tube is also connected to an angular or bell crank lever 18 rwhich is mounted upon a pivoted support 19, which support is connectedto the casting 16 through the instrumentality of an adjusting rod 20 tocompensate for the movement of the parts. The lever is provided with adepending arm 21 which is in turn pivotally connected with the tube, asshown at 22, and the inclined or longer arm of the lever, indicated bythe numeral 23, has connection with the actuating arm 24: of a valve 25controlling the supply of water to the boiler through a main feed waterpipe 26, as by means of a flexible connection or chain 27. This valve 25is disposed in a normally closed position and is maintained in thisposition when the water level is high and the water enters the expansiontube so that the latter is contracted and permits the arm 23 to beloweredand the arm 24: to close the valve 25. However, when the waterlevel becomes low and is displaced by steam through the pipe 17, thetube 13 will expand and rock the lever 18 on its pivot, and this willresult in the raising of the arm 23 and the arm 24: through theconnection 27 in to open the valve 25 and supply water to the boiler.

As before mentioned, it is common to connect the lower end of theexpansion tube communicating with the interior of the casting 16 withthe water space of thedrum or to the mud drum of the boiler, and ifconnected to only one of the steam drums it is evident that the waterlevel in the other two drums can have no influence on the regulator, andif connected to the mud drum, the water in each steam drum,'equally ornearly so, controls the water level in the expansion tube, and theresult is that the water in the tube stands at or near the average ofthe levels of he W te inth ee. dru med t ,7 sh vel a ot p v ed again t a:By th he n des ribed inven o s the feed water regulator is caused to beacted upon and respond to the highest water level in any drum for thepurposes specified and for this purpose all of the drums of the multipledrum boiler are connected to, the regulator independently or through asystem of pipes forming a manifold 28 which preferably communicates withthe casting 16. The lower end of the water gage.,is,con-

' ne oted, a conduit 36 to the manifold 28 while the upper end ofthegage isconnected to the, steam spaceof any of the drums; as

shown, -itisi connected to the 10. The

manifold is in turn connected with the drums throu gh theinstrumentality of branchconnections29, 30 and gl, each' cara rying avalve casing 32 having a seat 3 3."

with whicha valve in the form of a pivoted flap 3 4 cooperates, toproduce a check valve opening in one, direction only to treely per-JInitthe flow of Water'from the drums to the manifold, Each flap isfurther provided with arestricted opening 35 through which a minutequantity or volume "of watermay flowiunder increased pressure from theexpansiontube through the'manifold to the drums. Each valve casing 32 ispreferably provided with a removable plug or cap 36,

i to permit access to the valve for any dealwaysstand at a slightlylower level thansired purpose. If the openings 35 were notv provided thesystemvwould not operate, for the simple reason that the water would notbe able to flow from the regulator to the drums when it stood at ahigher level in the regulator than in the drums, so that by providingthe small holes through the flaps of Y the check valves this defect isovercome and the water in the feedwater regulator will the water in thedrum at the highest level, owing to the fact that there will beaconstant, though slight, flow of waterfrom this drum to the other twodrums throughthese small openings in the check valves. The

' difierence between thelevel of thewater in the drum having the highestlevel and that in the feed water regulator or device forgeneralnotification ofihigh" water corre-, sponds to the lost headresulting from the flow of water to the other drums, and this dependsupon-the size ofthe holes in the 2; t as ,meme t- I Ibis is d te he f stth tv ll-th pipes. are open at 'a l ime "W t r, f e- 5; the i nii l ttetl eamre Qfil nvent n r s s n the f ct t at t 'pirs as pen, bu y asdi ap ovid ng the awn s t r ugh t e ch k valve: he. hy:

a hcg ad ent is cau -to be alway l' s t p Whenf h at r? flows from onedr m Q i W ter 'mee f dift an i the" asewh i th Wate fla s tothe,same111111111-v through he. manif ldrfmm the other dWmS-Q By he,

ydra erad enti eing. les steep i the I 'Water ,flq l f o' a y drum}.hat. is 1% posit ve direction, than when it flows tethedrum, that is, inthe negative direction, is

mea tth ac hat ythe na wi h? vice ons ituting this. inven i ag 'ven ewdirection; or when on any two occasions the o vv ater"in the positive -dire ction will re- I qu re, alesser hydraulichead to produce it an the efi W o ater inf-a gative hydraulic headsavailabl in themanifold or inthe feed water regulator or in] a general notification device] and inany oftheidrurns are equal but in opposite directions,then in the postive direction agreat'er flow of W alter W111 be pro uced than in teinega ve irection. ,Th is, e tothe ct that th fiiilisf fall open inthepositive direction and the v esis ance is, e s. than that ofiered. i tneg ive dir c lon, When heval es W111 sea an lthe wa er must. passthrough pen= ng 5- I Thus, the device constituting this inven.-. tioncauses the hydraulic resistance of the pipe lines, or other connectingpassages from the respective drums to thefeed water regulator orfrornithe respective druins vto the manifold, if a manifold is used, toautomatically vary, upon reversal of the flow of thewater, giving lowhydraulic resistance to the flow of the water in the positive direc'tion, and higher hydraulic resistance to the I flow of the water in thenegative direction. The mechanical means by whichthe abovedescribedessential feature of this invention is'accomplishedjconsists ofthe check valves as described, and theratio of the area of each hole ina'valve mule area of each check through whichthe hole extends issmall,the

The

che ks v1 7 II Let-n number of drums in multiple drum I boiler. I A=area ofch'eck. I 9 ar a 93 h le extend g through heekf W Kt In thesystem of'general notification of undesirable or dangerously high Waterlevel,

115 magnitude depending upon the number of drum i t egmult rl oerfollowing general ,relations hold concerning the ratio of theholes tothe area of the" with or' witho'ut automatic regulation of the feedingof the water, the gage glass is connectedto the manifold 28, as shown at'36, and the g'ageglass constitutes a signal,

which might be a visual or audible one, operated upon by the-highestwater level. Without automatic regulation of the feed Water, throughautomatic actuation of the valve 25, the regulator is omitted and theoperation of the valve left to the attendant tobe operated upon thenotification being the steam space of a drum; of connectionos betweenall of the drums and the lower end of the water regulator, and meanslocated in said connections whereby the flow of Water from the drums tothe regulator is under less resistance than the flow in the oppositedirection. 7

2; A Water control for multiple drum boilers, embodying the combinationwith a multiple of drums and a. manifold connecting the drums; of meansassociated with the manifold and with the steam space of a drum tooperate and be affected by the water level and steam pressure in thedrum in which the water level is highest, and means located between said'manifold and each drum, whereby the flow of water in the direction ofthe first-mentioned means is under less resistance than the flow in theopposite direction. I

3. In combination, a plurality of steam drums of a boiler, a manifoldconnecting all of said drums, a feed-water regulator connected to saidmanifold and to the steam space of any one of the drums, a water gagealso connected to the manifold and to the steam space of any one of thedrums, and means positioned between each drum and the manifold whichafford a free flow fromv the drum to the manifold but a restricted flowin the opposite direction.

l. In combination, a plurality of boiler drums, a manifold connected tothe said drums, a valve between each drum and manifold for offering ahigher resistance to flow from the manifold to the drum than from thedrum to the manifold, and means adapted to be affected by the steampressure in one of the drums and connected to the manifold to beaffected by the hydraulic head therein.

5. In combination With a plurality of boiler drums, a manifoldconnecting all of said drums, a check valve from each of the drums tothe manifold having an opening affording a restricted flow from themanifold to the drum but a free flow from the drum to the manifold, andmeans connected to the steam space of any one of the drums and to themanifold so as to be affected by the hydraulic head therein.

6. In combination With a plurality of boiler drums, a manifoldconnecting all of said drums, a check valve from each of the drums tothe manifold, each of said check valves having an opening affording arestricted flow from the manifold to the drum and a free flow from thedrum to the manifold, the sum total of the cross-sectional areas of theopenings in all the check valves being less than the cross sectionalarea of any of the check valves, and means connected to the steam spaceof any one of the drums to be affected by the steam pressure thereof andalso connected to the manifold to be affected by the hydraulic head inthe manifold, substantially as and for the purpose set forth.

7 In combination With a plurality of steam drums of a boiler, a manifoldconnecting all of said drums, a check valve from each of the drums tothe manifold, each of. said check valves having an opening affording arestricted flow from the manifold to the drum While leaving anundisturbed flow from the drum to the manifold, a feed-Water regulatorconnected to the manifold and to the steam space of any one of thedrums, a Water gage connected to the steam space of any one of the drumsand to the manifold, the sum total of the cross sectional area of theopeningsin all the check valves being less than the'cross-sectional areaof any one of the check valves, substantially as and for the purpose setforth.

In testimony whereof We have signed our names to this specification inthe presence of two subscribing Witnesses.

Witnesses:

E. A. MARSCHALK, J. H. DEERE.

i Copies of this patent may be obtained for fiv'e cents each, byaddressing the Commissioner of Patents,

Washington, D. C.

